Hyperthyroidism in the geriatric population.

Although the thyroid gland can become overactive at any age, the syndrome of hyperthyroidism changes considerably in elderly persons. The principal reason is comorbidity. The patient over age 65 is much more likely than a young adult of 20 or 25 to have one or more preexisting disorders when the thyroid becomes overactive. In the elderly, therefore, the classic picture of hyperthyroidism--the constellation of irritability, sweating, palpitations without heart disease, weight loss despite good appetite, goiter, and warm, fine skin, familiar to all physicians--may never develop. Well before it might have appeared, a milder degree of thyroid hyperfunction may become manifest because of worsening of an underlying disease. Accordingly, the recognition of the thyroid disorder is often delayed. The purpose of this article is not so much to review hyperthyroidism as to delineate the special features found in geriatric patients and to describe a simple but effective scheme of evaluation.